The present disclosure relates to an image processing apparatus, an image processing method, and a program. In particular, the present disclosure relates to an image processing apparatus, an image processing method, and a program that perform processes for reducing noise in images and increasing the resolution of images.
In a case where image processing, such as an image noise reduction (NR) process, or a resolution increasing process, which is called, for example, a super resolution (SR) process that generates a high resolution image from a low resolution image, is to be performed, for example, processing in which a plurality of continually captured images containing the same subject are used is performed. Examples of the related art that discloses an image processing technology, such as noise reduction using a plurality of images, include Japanese Unexamined Patent Application Publication No. 2009-194700, and Japanese Unexamined Patent Application Publication No. 2009-290827.
In a case where the noise reduction process or the resolution increasing process is to be performed, effective noise reduction and increasing of resolution are realized by using many images. Therefore, for an apparatus that generates high-quality images, memories that store many images become necessary.
However, if an image processing apparatus is provided with many image storage memories, hardware becomes large, and the cost is increased. Therefore, a problem arises in that it is difficult for image-capturing devices for which there is a large demand for reduction in size, and low cost to be provided with such many memories.
Furthermore, in a case where noise reduction and increasing of resolution described above are to be performed in an image-capturing device, the following different images can become targets to be processed as images for the processing target:
(a) a RAW image that is generated by image-capturing elements, a so-called mosaic image formed of signals of pixels, of only specific color (for example, any one of RGB) corresponding to a color filter as a signal of each pixel,
(b) a full color image in which a color signal of RGB or the like is set in all the pixels by a color interpolation process for a mosaic image.
However, since the structure of these image signals is different, in the related art, processing is performed by using an individual dedicated circuit depending on which one of the image signals (a) and (b) is made to be a processing target. That is, there is no art that discloses a specific structure in which processing is performed on the two different signals by applying one common circuit.
As to how a circuit for performing noise reduction and increasing of resolution on these two different image signals is to be decreased in size so as to reduce the cost has become a challenge.